release/3.0.0

4 files changed, 60 insertions, 603 deletions

diff --git a/usr.bin/gcore/Makefile b/usr.bin/gcore/Makefile
index 7f6a3eed905ac..664813febb927 100644
--- a/usr.bin/gcore/Makefile
+++ b/usr.bin/gcore/Makefile
@@ -1,8 +1,7 @@
 #	@(#)Makefile	8.1 (Berkeley) 6/6/93
 
 PROG=	gcore
-SRCS=	elfcore.c gcore.c
-CFLAGS+=-Wall
+SRCS=	gcore.c
 DPADD=	${LIBKVM}
 LDADD=	-lkvm
 
diff --git a/usr.bin/gcore/elfcore.c b/usr.bin/gcore/elfcore.c
deleted file mode 100644
index af199ca8f705c..0000000000000
--- a/usr.bin/gcore/elfcore.c
+++ /dev/null
@@ -1,514 +0,0 @@
-/*-
- * Copyright (c) 1998 John D. Polstra
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- *
- *	$Id: elfcore.c,v 1.1 1998/10/19 19:42:18 jdp Exp $
- */
-
-#include <sys/param.h>
-#include <sys/lock.h>
-#include <sys/procfs.h>
-#include <vm/vm_param.h>
-#include <vm/vm.h>
-#include <vm/pmap.h>
-#include <vm/vm_map.h>
-#include <vm/vm_prot.h>
-#include <elf.h>
-#include <err.h>
-#include <errno.h>
-#include <fcntl.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-
-#include "extern.h"
-
-/*
- * Code for generating ELF core dumps.
- */
-
-typedef void (*segment_callback)(vm_map_entry_t, void *);
-
-/* Closure for cb_put_phdr(). */
-struct phdr_closure {
-	Elf_Phdr *phdr;		/* Program header to fill in */
-	Elf_Off offset;		/* Offset of segment in core file */
-};
-
-/* Closure for cb_size_segment(). */
-struct sseg_closure {
-	int count;		/* Count of writable segments. */
-	size_t size;		/* Total size of all writable segments. */
-};
-
-static void cb_put_phdr(vm_map_entry_t, void *);
-static void cb_size_segment(vm_map_entry_t, void *);
-static void each_writable_segment(vm_map_entry_t, segment_callback,
-    void *closure);
-static void elf_corehdr(int fd, pid_t, vm_map_entry_t, int numsegs,
-    void *hdr, size_t hdrsize);
-static void elf_puthdr(vm_map_entry_t, void *, size_t *,
-    const prstatus_t *, const prfpregset_t *, const prpsinfo_t *, int numsegs);
-static void elf_putnote(void *dst, size_t *off, const char *name, int type,
-    const void *desc, size_t descsz);
-static void freemap(vm_map_entry_t);
-static void readhdrinfo(pid_t, prstatus_t *, prfpregset_t *, prpsinfo_t *);
-static vm_map_entry_t readmap(pid_t);
-
-/*
- * Write an ELF coredump for the given pid to the given fd.
- */
-void
-elf_coredump(int fd, pid_t pid)
-{
-	vm_map_entry_t map;
-	struct sseg_closure seginfo;
-	void *hdr;
-	size_t hdrsize;
-	char memname[64];
-	int memfd;
-	Elf_Phdr *php;
-	int i;
-
-	/* Get the program's memory map. */
-	map = readmap(pid);
-
-	/* Size the program segments. */
-	seginfo.count = 0;
-	seginfo.size = 0;
-	each_writable_segment(map, cb_size_segment, &seginfo);
-
-	/*
-	 * Calculate the size of the core file header area by making
-	 * a dry run of generating it.  Nothing is written, but the
-	 * size is calculated.
-	 */
-	hdrsize = 0;
-	elf_puthdr(map, (void *)NULL, &hdrsize,
-	    (const prstatus_t *)NULL, (const prfpregset_t *)NULL,
-	    (const prpsinfo_t *)NULL, seginfo.count);
-
-	/*
-	 * Allocate memory for building the header, fill it up,
-	 * and write it out.
-	 */
-	hdr = malloc(hdrsize);
-	if ((hdr = malloc(hdrsize)) == NULL)
-		errx(1, "out of memory");
-	elf_corehdr(fd, pid, map, seginfo.count, hdr, hdrsize);
-
-	/* Write the contents of all of the writable segments. */
-	snprintf(memname, sizeof memname, "/proc/%d/mem", pid);
-	if ((memfd = open(memname, O_RDONLY)) == -1)
-		err(1, "cannot open %s", memname);
-
-	php = (Elf_Phdr *)((char *)hdr + sizeof(Elf_Ehdr)) + 1;
-	for (i = 0;  i < seginfo.count;  i++) {
-		int nleft = php->p_filesz;
-
-		lseek(memfd, (off_t)php->p_vaddr, SEEK_SET);
-		while (nleft > 0) {
-			char buf[8*1024];
-			int nwant;
-			int ngot;
-
-			nwant = nleft;
-			if (nwant > sizeof buf)
-				nwant = sizeof buf;
-			ngot = read(memfd, buf, nwant);
-			if (ngot == -1)
-				err(1, "read from %s", memname);
-			if (ngot < nwant)
-				errx(1, "short read from %s:"
-				    " wanted %d, got %d\n", memname,
-				    nwant, ngot);
-			ngot = write(fd, buf, nwant);
-			if (ngot == -1)
-				err(1, "write of segment %d failed", i);
-			if (ngot != nwant)
-				errx(1, "short write");
-			nleft -= nwant;
-		}
-		php++;
-	}
-	close(memfd);
-	free(hdr);
-	freemap(map);
-}
-
-/*
- * A callback for each_writable_segment() to write out the segment's
- * program header entry.
- */
-static void
-cb_put_phdr(vm_map_entry_t entry, void *closure)
-{
-	struct phdr_closure *phc = (struct phdr_closure *)closure;
-	Elf_Phdr *phdr = phc->phdr;
-
-	phc->offset = round_page(phc->offset);
-
-	phdr->p_type = PT_LOAD;
-	phdr->p_offset = phc->offset;
-	phdr->p_vaddr = entry->start;
-	phdr->p_paddr = 0;
-	phdr->p_filesz = phdr->p_memsz = entry->end - entry->start;
-	phdr->p_align = PAGE_SIZE;
-	phdr->p_flags = 0;
-	if (entry->protection & VM_PROT_READ)
-		phdr->p_flags |= PF_R;
-	if (entry->protection & VM_PROT_WRITE)
-		phdr->p_flags |= PF_W;
-	if (entry->protection & VM_PROT_EXECUTE)
-		phdr->p_flags |= PF_X;
-
-	phc->offset += phdr->p_filesz;
-	phc->phdr++;
-}
-
-/*
- * A callback for each_writable_segment() to gather information about
- * the number of segments and their total size.
- */
-static void
-cb_size_segment(vm_map_entry_t entry, void *closure)
-{
-	struct sseg_closure *ssc = (struct sseg_closure *)closure;
-
-	ssc->count++;
-	ssc->size += entry->end - entry->start;
-}
-
-/*
- * For each segment in the given memory map, call the given function
- * with a pointer to the map entry and some arbitrary caller-supplied
- * data.
- */
-static void
-each_writable_segment(vm_map_entry_t map, segment_callback func, void *closure)
-{
-	vm_map_entry_t entry;
-
-	for (entry = map;  entry != NULL;  entry = entry->next)
-		(*func)(entry, closure);
-}
-
-/*
- * Write the core file header to the file, including padding up to
- * the page boundary.
- */
-static void
-elf_corehdr(int fd, pid_t pid, vm_map_entry_t map, int numsegs, void *hdr,
-    size_t hdrsize)
-{
-	size_t off;
-	prstatus_t status;
-	prfpregset_t fpregset;
-	prpsinfo_t psinfo;
-
-	/* Gather the information for the header. */
-	readhdrinfo(pid, &status, &fpregset, &psinfo);
-
-	/* Fill in the header. */
-	memset(hdr, 0, hdrsize);
-	off = 0;
-	elf_puthdr(map, hdr, &off, &status, &fpregset, &psinfo, numsegs);
-
-	/* Write it to the core file. */
-	if (write(fd, hdr, hdrsize) == -1)
-		err(1, "write");
-}
-
-/*
- * Generate the ELF coredump header into the buffer at "dst".  "dst" may
- * be NULL, in which case the header is sized but not actually generated.
- */
-static void
-elf_puthdr(vm_map_entry_t map, void *dst, size_t *off, const prstatus_t *status,
-    const prfpregset_t *fpregset, const prpsinfo_t *psinfo, int numsegs)
-{
-	size_t ehoff;
-	size_t phoff;
-	size_t noteoff;
-	size_t notesz;
-
-	ehoff = *off;
-	*off += sizeof(Elf_Ehdr);
-
-	phoff = *off;
-	*off += (numsegs + 1) * sizeof(Elf_Phdr);
-
-	noteoff = *off;
-	elf_putnote(dst, off, "FreeBSD", NT_PRSTATUS, status,
-	    sizeof *status);
-	elf_putnote(dst, off, "FreeBSD", NT_FPREGSET, fpregset,
-	    sizeof *fpregset);
-	elf_putnote(dst, off, "FreeBSD", NT_PRPSINFO, psinfo,
-	    sizeof *psinfo);
-	notesz = *off - noteoff;
-
-	/* Align up to a page boundary for the program segments. */
-	*off = round_page(*off);
-
-	if (dst != NULL) {
-		Elf_Ehdr *ehdr;
-		Elf_Phdr *phdr;
-		struct phdr_closure phc;
-
-		/*
-		 * Fill in the ELF header.
-		 */
-		ehdr = (Elf_Ehdr *)((char *)dst + ehoff);
-		ehdr->e_ident[EI_MAG0] = ELFMAG0;
-		ehdr->e_ident[EI_MAG1] = ELFMAG1;
-		ehdr->e_ident[EI_MAG2] = ELFMAG2;
-		ehdr->e_ident[EI_MAG3] = ELFMAG3;
-		ehdr->e_ident[EI_CLASS] = ELF_CLASS;
-		ehdr->e_ident[EI_DATA] = ELF_DATA;
-		ehdr->e_ident[EI_VERSION] = EV_CURRENT;
-		ehdr->e_ident[EI_PAD] = 0;
-		strncpy(ehdr->e_ident + EI_BRAND, "FreeBSD",
-		    EI_NIDENT - EI_BRAND);
-		ehdr->e_type = ET_CORE;
-		ehdr->e_machine = ELF_ARCH;
-		ehdr->e_version = EV_CURRENT;
-		ehdr->e_entry = 0;
-		ehdr->e_phoff = phoff;
-		ehdr->e_flags = 0;
-		ehdr->e_ehsize = sizeof(Elf_Ehdr);
-		ehdr->e_phentsize = sizeof(Elf_Phdr);
-		ehdr->e_phnum = numsegs + 1;
-		ehdr->e_shentsize = sizeof(Elf_Shdr);
-		ehdr->e_shnum = 0;
-		ehdr->e_shstrndx = SHN_UNDEF;
-
-		/*
-		 * Fill in the program header entries.
-		 */
-		phdr = (Elf_Phdr *)((char *)dst + phoff);
-
-		/* The note segement. */
-		phdr->p_type = PT_NOTE;
-		phdr->p_offset = noteoff;
-		phdr->p_vaddr = 0;
-		phdr->p_paddr = 0;
-		phdr->p_filesz = notesz;
-		phdr->p_memsz = 0;
-		phdr->p_flags = 0;
-		phdr->p_align = 0;
-		phdr++;
-
-		/* All the writable segments from the program. */
-		phc.phdr = phdr;
-		phc.offset = *off;
-		each_writable_segment(map, cb_put_phdr, &phc);
-	}
-}
-
-/*
- * Emit one note section to "dst", or just size it if "dst" is NULL.
- */
-static void
-elf_putnote(void *dst, size_t *off, const char *name, int type,
-    const void *desc, size_t descsz)
-{
-	Elf_Note note;
-
-	note.n_namesz = strlen(name) + 1;
-	note.n_descsz = descsz;
-	note.n_type = type;
-	if (dst != NULL)
-		bcopy(&note, (char *)dst + *off, sizeof note);
-	*off += sizeof note;
-	if (dst != NULL)
-		bcopy(name, (char *)dst + *off, note.n_namesz);
-	*off += roundup2(note.n_namesz, sizeof(Elf_Size));
-	if (dst != NULL)
-		bcopy(desc, (char *)dst + *off, note.n_descsz);
-	*off += roundup2(note.n_descsz, sizeof(Elf_Size));
-}
-
-/*
- * Free the memory map.
- */
-static void
-freemap(vm_map_entry_t map)
-{
-	while (map != NULL) {
-		vm_map_entry_t next = map->next;
-		free(map);
-		map = next;
-	}
-}
-
-/*
- * Read the process information necessary to fill in the core file's header.
- */
-static void
-readhdrinfo(pid_t pid, prstatus_t *status, prfpregset_t *fpregset,
-    prpsinfo_t *psinfo)
-{
-	char name[64];
-	char line[256];
-	int fd;
-	int i;
-	int n;
-
-	memset(status, 0, sizeof *status);
-	status->pr_version = PRSTATUS_VERSION;
-	status->pr_statussz = sizeof(prstatus_t);
-	status->pr_gregsetsz = sizeof(gregset_t);
-	status->pr_fpregsetsz = sizeof(fpregset_t);
-	status->pr_osreldate = __FreeBSD_version;
-	status->pr_pid = pid;
-
-	memset(fpregset, 0, sizeof *fpregset);
-
-	memset(psinfo, 0, sizeof *psinfo);
-	psinfo->pr_version = PRPSINFO_VERSION;
-	psinfo->pr_psinfosz = sizeof(prpsinfo_t);
-
-	/* Read the general registers. */
-	snprintf(name, sizeof name, "/proc/%d/regs", pid);
-	if ((fd = open(name, O_RDONLY)) == -1)
-		err(1, "cannot open %s", name);
-	if ((n = read(fd, &status->pr_reg, sizeof status->pr_reg)) == -1)
-		err(1, "read error from %s", name);
-	if (n < sizeof status->pr_reg)
-		errx(1, "short read from %s: wanted %u, got %d", name,
-		    sizeof status->pr_reg, n);
-	close(fd);
-
-	/* Read the floating point registers. */
-	snprintf(name, sizeof name, "/proc/%d/fpregs", pid);
-	if ((fd = open(name, O_RDONLY)) == -1)
-		err(1, "cannot open %s", name);
-	if ((n = read(fd, fpregset, sizeof *fpregset)) == -1)
-		err(1, "read error from %s", name);
-	if (n < sizeof *fpregset)
-		errx(1, "short read from %s: wanted %u, got %d", name,
-		    sizeof *fpregset, n);
-	close(fd);
-
-	/* Read and parse the process status. */
-	snprintf(name, sizeof name, "/proc/%d/status", pid);
-	if ((fd = open(name, O_RDONLY)) == -1)
-		err(1, "cannot open %s", name);
-	if ((n = read(fd, line, sizeof line - 1)) == -1)
-		err(1, "read error from %s", name);
-	if (n > MAXCOMLEN)
-		n = MAXCOMLEN;
-	for (i = 0;  i < n && line[i] != ' ';  i++)
-		psinfo->pr_fname[i] = line[i];
-	strncpy(psinfo->pr_psargs, psinfo->pr_fname, PRARGSZ);
-	close(fd);
-}
-
-/*
- * Read the process's memory map using procfs, and return a list of
- * VM map entries.  Only the non-device read/writable segments are
- * returned.  The map entries in the list aren't fully filled in; only
- * the items we need are present.
- */
-static vm_map_entry_t
-readmap(pid_t pid)
-{
-	char mapname[64];
-	int mapfd;
-	ssize_t mapsize;
-	size_t bufsize;
-	char *mapbuf;
-	int pos;
-	vm_map_entry_t map;
-	vm_map_entry_t *linkp;
-
-	snprintf(mapname, sizeof mapname, "/proc/%d/map", pid);
-	if ((mapfd = open(mapname, O_RDONLY)) == -1)
-		err(1, "cannot open %s", mapname);
-
-	/*
-	 * Procfs requires (for consistency) that the entire memory map
-	 * be read with a single read() call.  Start with a reasonbly sized
-	 * buffer, and double it until it is big enough.
-	 */
-	bufsize = 8 * 1024;
-	mapbuf = NULL;
-	for ( ; ; ) {
-		if ((mapbuf = realloc(mapbuf, bufsize)) == NULL)
-			errx(1, "out of memory");
-		mapsize = read(mapfd, mapbuf, bufsize);
-		if (mapsize != -1 || errno != EFBIG)
-			break;
-		bufsize *= 2;
-		/* This lseek shouldn't be necessary, but it is. */
-		lseek(mapfd, (off_t)0, SEEK_SET);
-	}
-	if (mapsize == -1)
-		err(1, "read error from %s", mapname);
-	if (mapsize == 0)
-		errx(1, "empty map file %s", mapname);
-	close(mapfd);
-
-	pos = 0;
-	map = NULL;
-	linkp = &map;
-	while (pos < mapsize) {
-		vm_map_entry_t ent;
-		vm_offset_t start;
-		vm_offset_t end;
-		char prot[4];
-		char type[16];
-		int n;
-		int len;
-
-		len = 0;
-		n = sscanf(mapbuf + pos, "%x %x %*d %*d %*d %3[-rwx]"
-		    " %*d %*d %*x %*s %*s %16s%*[\n]%n",
-		    &start, &end, prot, type, &len);
-		if (n != 4)
-			errx(1, "ill-formed line in %s", mapname);
-		pos += len;
-
-		/* Ignore segments of the wrong kind, and unwritable ones */
-		if (strncmp(prot, "rw", 2) != 0 ||
-		    (strcmp(type, "default") != 0 &&
-		    strcmp(type, "vnode") != 0 &&
-		    strcmp(type, "swap") != 0))
-			continue;
-
-		if ((ent = (vm_map_entry_t)calloc(1, sizeof *ent)) == NULL)
-			errx(1, "out of memory");
-		ent->start = start;
-		ent->end = end;
-		ent->protection = VM_PROT_READ | VM_PROT_WRITE;
-		if (prot[2] == 'x')
-		    ent->protection |= VM_PROT_EXECUTE;
-
-		*linkp = ent;
-		linkp = &ent->next;
-	}
-	free(mapbuf);
-	return map;
-}
diff --git a/usr.bin/gcore/extern.h b/usr.bin/gcore/extern.h
index f157e531a5f3a..3dccafe70845c 100644
--- a/usr.bin/gcore/extern.h
+++ b/usr.bin/gcore/extern.h
@@ -33,9 +33,5 @@
  *	@(#)extern.h	8.1 (Berkeley) 6/6/93
  */
 
-#include <sys/types.h>
-#include <kvm.h>
-
 void	err __P((int, const char *, ...));
-void	elf_coredump __P((int, pid_t));
 void	md_core __P((kvm_t *, int, struct kinfo_proc *));
diff --git a/usr.bin/gcore/gcore.c b/usr.bin/gcore/gcore.c
index 4702003b8afc1..8ab7b0bdbe613 100644
--- a/usr.bin/gcore/gcore.c
+++ b/usr.bin/gcore/gcore.c
@@ -42,7 +42,7 @@ static const char copyright[] =
 static char sccsid[] = "@(#)gcore.c	8.2 (Berkeley) 9/23/93";
 #endif
 static const char rcsid[] =
-	"$Id: gcore.c,v 1.12 1998/10/22 04:02:37 jdp Exp $";
+	"$Id: gcore.c,v 1.9 1998/09/14 10:09:30 des Exp $";
 #endif /* not lint */
 
 /*
@@ -79,19 +79,17 @@ static const char rcsid[] =
 
 #include "extern.h"
 
-static void	core __P((int, int, struct kinfo_proc *));
-static void	datadump __P((int, int, struct proc *, u_long, int));
-static void	killed __P((int));
-static void	restart_target __P((void));
-static void	usage __P((void)) __dead2;
-static void	userdump __P((int, struct proc *, u_long, int));
+void	core __P((int, int, struct kinfo_proc *));
+void	datadump __P((int, int, struct proc *, u_long, int));
+void	usage __P((void));
+void	userdump __P((int, struct proc *, u_long, int));
 
 kvm_t *kd;
 /* XXX undocumented routine, should be in kvm.h? */
 ssize_t kvm_uread __P((kvm_t *, const struct proc *, u_long, char *, size_t));
 
+
 static int data_offset;
-static pid_t pid;
 
 int
 main(argc, argv)
@@ -99,12 +97,11 @@ main(argc, argv)
 	char *argv[];
 {
 	register struct proc *p;
-	struct kinfo_proc *ki = NULL;
+	struct kinfo_proc *ki;
 	struct exec exec;
-	int ch, cnt, efd, fd, sflag, uid;
+	int ch, cnt, efd, fd, pid, sflag, uid;
 	char *binfile, *corefile;
 	char errbuf[_POSIX2_LINE_MAX], fname[MAXPATHLEN + 1];
-	int is_aout;
 
 	sflag = 0;
 	corefile = NULL;
@@ -140,53 +137,27 @@ main(argc, argv)
 		usage();
 	}
 
-	efd = open(binfile, O_RDONLY, 0);
-	if (efd < 0)
-		err(1, "%s", binfile);
+	kd = kvm_openfiles(0, 0, 0, O_RDONLY, errbuf);
+	if (kd == NULL)
+		errx(1, "%s", errbuf);
 
-	cnt = read(efd, &exec, sizeof(exec));
-	if (cnt != sizeof(exec))
-		errx(1, "%s exec header: %s",
-		    binfile, cnt > 0 ? strerror(EIO) : strerror(errno));
-	if (!N_BADMAG(exec)) {
-		is_aout = 1;
-		/*
-		 * This legacy a.out support uses the kvm interface instead
-		 * of procfs.
-		 */
-		kd = kvm_openfiles(0, 0, 0, O_RDONLY, errbuf);
-		if (kd == NULL)
-			errx(1, "%s", errbuf);
-
-		uid = getuid();
-
-		ki = kvm_getprocs(kd, KERN_PROC_PID, pid, &cnt);
-		if (ki == NULL || cnt != 1)
-			errx(1, "%d: not found", pid);
-
-		p = &ki->kp_proc;
-		if (ki->kp_eproc.e_pcred.p_ruid != uid && uid != 0)
-			errx(1, "%d: not owner", pid);
-
-		if (p->p_stat == SZOMB)
-			errx(1, "%d: zombie", pid);
-
-		if (p->p_flag & P_WEXIT)
-			errx(1, "%d: process exiting", pid);
-		if (p->p_flag & P_SYSTEM)	/* Swapper or pagedaemon. */
-			errx(1, "%d: system process", pid);
-		if (exec.a_text != ptoa(ki->kp_eproc.e_vm.vm_tsize))
-			errx(1, "The executable %s does not belong to"
-			    " process %d!\n"
-			    "Text segment size (in bytes): executable %ld,"
-			    " process %d", binfile, pid, exec.a_text, 
-			     ptoa(ki->kp_eproc.e_vm.vm_tsize));
-		data_offset = N_DATOFF(exec);
-	} else if (IS_ELF(*(Elf_Ehdr *)&exec)) {
-		is_aout = 0;
-		close(efd);
-	} else
-		errx(1, "Invalid executable file");
+	uid = getuid();
+
+	ki = kvm_getprocs(kd, KERN_PROC_PID, pid, &cnt);
+	if (ki == NULL || cnt != 1)
+		errx(1, "%d: not found", pid);
+
+	p = &ki->kp_proc;
+	if (ki->kp_eproc.e_pcred.p_ruid != uid && uid != 0)
+		errx(1, "%d: not owner", pid);
+
+	if (p->p_stat == SZOMB)
+		errx(1, "%d: zombie", pid);
+
+	if (p->p_flag & P_WEXIT)
+		errx(1, "%d: process exiting", pid);
+	if (p->p_flag & P_SYSTEM)	/* Swapper or pagedaemon. */
+		errx(1, "%d: system process", pid);
 
 	if (corefile == NULL) {
 		(void)snprintf(fname, sizeof(fname), "core.%d", pid);
@@ -196,21 +167,41 @@ main(argc, argv)
 	if (fd < 0)
 		err(1, "%s", corefile);
 
-	if (sflag) {
-		signal(SIGHUP, killed);
-		signal(SIGINT, killed);
-		signal(SIGTERM, killed);
-		if (kill(pid, SIGSTOP) == -1)
-			err(1, "%d: stop signal", pid);
-		atexit(restart_target);
+	efd = open(binfile, O_RDONLY, 0);
+	if (efd < 0)
+		err(1, "%s", binfile);
+
+	cnt = read(efd, &exec, sizeof(exec));
+	if (cnt != sizeof(exec))
+		errx(1, "%s exec header: %s",
+		    binfile, cnt > 0 ? strerror(EIO) : strerror(errno));
+	if (N_BADMAG(exec)) {
+		const Elf_Ehdr *ehdr = (const Elf_Ehdr *)&exec;
+
+		if (IS_ELF(*ehdr))
+			errx(1, "ELF executables are not supported yet");
+		errx(1, "Invalid executable file");
 	}
 
-	if (is_aout)
-		core(efd, fd, ki);
-	else
-		elf_coredump(fd, pid);
+	/* check the text segment size of the executable and the process */
+	if (exec.a_text != ptoa(ki->kp_eproc.e_vm.vm_tsize))
+		errx(1, 
+		     "The executable %s does not belong to process %d!\n"
+		     "Text segment size (in bytes): executable %d, process %d",
+		     binfile, pid, exec.a_text, 
+		     ptoa(ki->kp_eproc.e_vm.vm_tsize));
+
+	data_offset = N_DATOFF(exec);
+
+	if (sflag && kill(pid, SIGSTOP) < 0)
+		err(1, "%d: stop signal", pid);
 
+	core(efd, fd, ki);
+
+	if (sflag && kill(pid, SIGCONT) < 0)
+		err(1, "%d: continue signal", pid);
 	(void)close(fd);
+
 	exit(0);
 }
 
@@ -295,21 +286,6 @@ datadump(efd, fd, p, addr, npage)
 	}
 }
 
-static void
-killed(sig)
-	int sig;
-{
-	restart_target();
-	signal(sig, SIG_DFL);
-	kill(getpid(), sig);
-}
-
-static void
-restart_target()
-{
-	kill(pid, SIGCONT);
-}
-
 void
 userdump(fd, p, addr, npage)
 	register int fd;